State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China; Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, Northwest A&F University, Yangling, Shaanxi 712100, China.
Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjian Airport Economic Area, Tianjin 300308, China.
Microbiol Res. 2019 Mar;220:32-41. doi: 10.1016/j.micres.2018.12.002. Epub 2018 Dec 6.
The type VI secretion system (T6SS) is a versatile molecular machinery widely distributed in Gram-negative bacteria. The activity of the T6SS is tightly regulated by various mechanisms, including quorum sensing (QS), iron concentration, and transcriptional regulators. Here we demonstrated that the stringent response regulator, RelA, contributes to bacterial resistance to multiple environmental stresses in Yersinia pseudotuberculosis. We also revealed that the stress resistance function of stringent response (SR) was partially mediated by the general stress response T6SS4 system. RelA positively regulates the expression of T6SS4 to combat various stresses in response to nutrition starvation collectively mediated by the RovM and RovA regulators. These findings revealed not only the important role of T6SS4 in SR induced stress resistance, but also a new pathway to regulate T6SS4 expression in response to starvation stress.
VI 型分泌系统（T6SS）是一种广泛分布于革兰氏阴性菌中的多功能分子机器。T6SS 的活性受到多种机制的严格调控，包括群体感应（QS）、铁浓度和转录调节因子。在这里，我们证明了严格反应调节剂 RelA 有助于假结核耶尔森氏菌对多种环境压力的抵抗。我们还揭示了严格反应（SR）的应激抗性功能部分由一般应激反应 T6SS4 系统介导。RelA 正向调节 T6SS4 的表达，以共同应对罗维 M 和罗维 A 调节剂介导的营养饥饿引起的各种应激。这些发现不仅揭示了 T6SS4 在 SR 诱导的应激抗性中的重要作用，还揭示了一种新的途径来调节 T6SS4 的表达以应对饥饿应激。
